The die rolls utilized for continuous rotary die cutting of web materials must be manufactured with a high degree of accuracy, to ensure smooth and true running in the die-cutting press and to produce work of good quality over extended periods of time. Therefore, they are quite expensive to produce. Conventionally, such die-cutting rolls have a cylindrical body portion with integrally formed axle portions extending outwardly from each opposite end; it is crucial that the axle portions, as well as the central body portion, be precisely machined to provide the necessary operating characteristics. Accordingly, a substantial part of the expense involved in manufacturing the conventional die-cutting rolls is attributable to the time, labor and materials required to produce the shaft portions.
In addition, because of the standard design utilized for such die rolls, their use tends to be limited in terms of web direction and press size. Obviously, a roll intended for relatively wide web will frequently be too long to fit into a narrow web press. Moreover, because the shaft portions will generally be of different lengths (to accommodate the drive gear on one end), considerable reworking must be carried out before they can be used in the reverse direction. Reversible die blanks are of course available, but they tend to be especially expensive, and can be used only in presses that are either originally designed or extensively modified to accommodate them.
In addition to the foregoing, standard die-cutting rolls typically fail to afford all of the convenience in use and advantageous features that might be desired. For example, installation and positioning of the die is oftentimes quite arduous, and adjustment of roll position during operation of the press is possible only with considerable difficulty, if at all. Moreover, the means by which the roll is maintained in contact with the web tends to be less than optimal, particularly insofar as load balance and roll movement and deflection are concerned. Finally, presently existing equipment of the sort here involved tends to require considerable attention for the proper lubrication of numerous wear points, and to subject the press frame and bearing members to excessive stresses, ultimately resulting in distortions and the need to replace worn parts with undue frequency.
Accordingly, it is a primary object of the present invention to provide a novel die-cutting roll assembly utilizing a modified die roll having no integrally formed shaft portions, and which is therefore relatively inexpensive to manufacture.
It is also an object of the invention to provide such an assembly in which die-cutting rolls of different lengths may readily be employed, and wherein the direction of die operation may be reversed with relative facility.
An additional object of the invention is to provide novel means by which adjustment of the lateral position of the cutting roll can readily be effected during operation of the press.
Another object of the invention is to provide novel support means for a die-cutting roll, from which standard bearing blocks are eliminated, thus reducing the lubrication requirements for the system, and by which undesirable loading upon the press and the associated mountings can be minimized.
Yet another object of the invention is to provide a novel die roll assist adaptor for use in conjunction with such a shaftless die, which adaptor facilitates initial installation and positioning of the die roll, provides a desirable mass effect to reduce bounce and shock transmission, and can be used to equalize loading upon the die.
A further object of the invention is to simply and economically provide novel apparatus having the foregoing features and advantages, the use of which requires no major modification to conventional rotary die-cutting presses.
Still further objects are to provide a novel implement for temporarily supporting the die roll upon the anvil roll during setting-up of the die-cutting station of the press, and a novel method in which the implement is employed.